The indeterminate nature of a peanut plant — and the fact that it puts on its fruit underground — add to the complexities of determining when to dig a crop. But a lot can be won and a lot can be lost based on your decision, says Wilson Faircloth, research agronomist with the National Peanut Research Laboratory in Dawson, Ga.

“You can get a lot of gain in yield sometimes in the final 20 days of a peanut’s production cycle,” says Faircloth. “Some peanuts put on 30 percent of their growth in the last two to three weeks of the season — that’s huge. When it comes to economics, we’ve got to make the best decision possible when it comes to digging peanuts.”

According to the hull-scrape method, approximately 140 days can be an optimal peanut digging time. “But on some of these varieties, there might be a little bit left on the table yet that we didn’t account for. That’s why we’re looking at new methods and ideas to make sure we’re at the top of the curve and not at the bottom end of it,” says Faircloth.

A few late-maturity cultivars never quit gaining in value when researchers stopped sampling at 154 days, he says. When those peanuts were dug at about the 145-day mark, money was left in the field, says Faircloth, because the maturity prediction date was not accurate.

“When do I dig?” remains a big question for growers, he says. “We have the hull-scrape method to help determine when we dig. And a lot of times, we start digging whenever our neighbors start. But the hull-scrape method is a very accurate tool, and sometimes, we determine when to dig by looking at the calendar. You look at the day you planted and count the days until maturity,” he says.

The truth is, says Faircloth, that neither one of these methods by itself is a good idea. “But we can put all of them together to formulate an educated guess on when is the right time to dig peanuts.”

Since peanuts are underground, growers can’t just ride by a field, take a quick look, and tell if they’re ready to dig. “And you can’t put them back once you dig them, so you have to be spot on.”

With the hull-scrape method, growers can place the pods on a profile board according to color class. Whenever there are accumulations in the black regions, you can predict a pretty accurate digging date, says Faircloth. A uniform curve on the board indicates that the pods all were set at one time over the course of a season.

Sometimes, the board indicates you have two crops of peanuts, he says. “You can have a crop that put on early — as it should have — and a crop that put on later. More than likely, you had a weather event that caused a decrease in pod set, and then conditions improved later in the season. This can cause a farmer to get into a guessing game, wondering how much of the crop he can afford to wait on, and how much he might lose if he waits for the late crop to mature,” says Faircloth.